Build System Overview

- Makefile.PL calls GHC to compile Setup.hs to ./Setup.exe.
- Makefile.PL writes a Makefile that will call util/build_pugs.pl
  upon "make".
- build_pugs.pl writes a Pugs.cabal file based on the flags given in
  the Makefile.
- build_pugs.pl calls ./Setup.exe.
- Setup.exe builds dist/build/libHSPugs-6.XXX.YYY.a and returns to
  build_pugs.pl.
- build_pugs.pl calls GHC to build ./pugs.exe
  (by simply linking the freshly built libHSPugs package with src/Main.hs).